JPH05102930A - Parallel optical transmitting device - Google Patents

Abstract

PURPOSE:To attain the synchronous transmission of parallel data without equalizing the lengths of optical wirings by transmitting the reference optical signals synchronous with each other after superposing them on the data optical signals for each channel and controlling the signal delayed variables in terms of a circuit. CONSTITUTION:A composite optical signal is produced by synthesizing the output light of a light emitting element 3 which outputs the data optical signals of different wavelengths and the output light of a light emitting element 4 which outputs the reference optical signals through an optical multiplexing element 5. Such a composite optical signal is outputted from an optical output terminal 6 of an optical transmission circuit 1 through an optical wiring 15. An optical reception circuit 7 separates the input optical signal into a date optical signal and a reference optical signal by an optical demultiplexing element 9. Then both signals are converted into the electric signals by the light receiving elements 10 and 11 and then delayed by the electric signal delay circuits 12 and 13. The reference signal of each channel is inputted to a phase comparator 16, and the delayed variable of the circuit 13 is properly set for each channel so that the synchronization is secured among the reference signals. Under such conditions, the delayed variable of the circuit 12 is set equal to that of the circuit 13 so that the synchronization is secured among the data signals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parallel optical transmission device for transmitting a plurality of optical signals in parallel.

[0002]

2. Description of the Related Art Conventionally, as one method of data transmission,
Parallel data transmission is used in which a plurality of electric signals are transmitted in parallel as electric signals by using a plurality of electric wirings.
In recent years, with the increasing demand for high-speed, large-capacity data transmission in fields such as communication-related devices and computers, conventional parallel data transmission for transmitting electrical signals in parallel has limited transmission speed and Problems such as the number limitation are becoming apparent. Therefore, parallel optical transmission has been proposed in which an electrical signal is converted into an optical signal and then the optical signal is transmitted in parallel using a plurality of optical wirings.

FIG. 4 shows the configuration of a conventional parallel optical transmission device. As shown in FIG. 4, the optical transmission circuit 1 includes an electric signal processing device 2 and a light emitting element 3, and outputs an optical signal from an optical output terminal 6. The optical receiving circuit 7 includes a light receiving element 10 that receives an optical signal input from the optical input terminal 8 and an electric signal processing device 14. However, if there is a difference in the length of the optical wiring 15 that connects the optical transmission circuit 1 and the optical reception circuit 7,
There is a difference in the delay time of the optical signal transmitted through each channel, and there is a difference in the delay time between the electrical signals reproduced based on this optical signal, that is, there is a synchronization shift, and accurate parallel data transmission can be performed. There was a problem of not having. Particularly, in the parallel optical transmitter configured by using a plurality of optical transmitter circuits, the difference in the distance between the input and output terminals is large depending on the channel.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a parallel optical transmission device capable of performing parallel data transmission in which signals are synchronized with each other without equalizing the length of optical wiring.

[0005]

A parallel optical transmission apparatus of the present invention has an optical transmission circuit and an optical reception circuit, and the optical transmission circuit includes a light emitting element A for outputting a data optical signal and a reference light. The light emitting element B that outputs a signal and the light combining element that combines the output light of the light emitting element A and the output light of the light emitting element B are used, and the output light wavelength of the light emitting element A and the light emitting element B Output optical wavelengths are different from each other, and a composite optical signal obtained by combining the data optical signal and the reference optical signal is output from the optical transmission circuit, and the optical receiving circuit converts the composite optical signal to the data optical signal. An optical demultiplexing element for separating the reference optical signal, a light receiving element A for converting the data optical signal into an electric signal, a light receiving element B for converting the reference optical signal into an electric signal, and an electric light by each light receiving element A An electrical signal delay circuit A for delaying a data signal converted into a signal, and a receiving circuit Configure with a electrical signal delay circuit B for delaying the reference signal converted into an electrical signal by element B,
The delay amounts of the electric signal delay circuit A and the electric signal delay circuit B are set to be equal, and the electric signal delay circuit A of another channel is set.
And the delay amount is set independently of the electric signal delay circuit B and arbitrarily.

The optical receiving circuit further comprises an optical signal delay circuit for delaying the composite optical signal, an optical demultiplexing element for separating the composite optical signal into the data optical signal and the reference optical signal, and the data optical signal. A light receiving element A for converting a signal into an electric signal and a light receiving element B for converting the reference optical signal into an electric signal are provided, and the delay amount of the optical signal delay circuit is independently and arbitrarily set for each channel. May be. Further, the optical receiving circuit further comprises an optical demultiplexing element for separating the composite optical signal into the data optical signal and the reference optical signal, an optical signal delay circuit A for delaying the data optical signal, and the reference optical signal. Optical signal delay circuit B, a light receiving element A for converting the data optical signal into an electrical signal, and a light receiving element B for converting the reference optical signal into an electrical signal. The delay amounts of the optical signal delay circuits B are set to be equal to each other, independently of the optical signal delay circuits A and B of other channels,
In addition, the delay amount may be set arbitrarily.

[0007]

Embodiments of the present invention will be described in detail below with reference to the drawings. Embodiment 1 A first embodiment according to the present invention is shown in FIG. The optical transmission circuit 1 shown in this embodiment includes an electric signal processing device 2, a light emitting element (A) 3 for converting a data signal into a data optical signal, a light emitting element (B) 4 for converting a reference signal into a reference optical signal, and data. It is composed of an optical multiplexing element 5 for multiplexing the optical signal and the reference optical signal. The output light wavelength of the light emitting element 3 and the output light wavelength of the light emitting element 4 are different, and the optical output terminal 6 outputs a composite optical signal obtained by combining optical signals of different wavelengths through the optical wiring 15. The optical receiving circuit 7 includes an optical demultiplexer 9 for separating an optical signal input from the optical input terminal 8 into optical signals (data optical signal and reference optical signal) having different wavelengths, and an optical signal for the data optical signal and the reference optical signal. Light receiving element (A) 10 to convert into light receiving element (B) 1
1, electrical signal delay circuit (A) 12 that delays the data signal and reference signal converted to electrical signal ・ Electrical signal delay circuit (B) 13
And an electric signal processing device 14.

The synchronized reference optical signal is superimposed on the data optical signal for each channel and transmitted, and the optical receiving circuit 7
The input optical signal is separated into a data optical signal and a reference optical signal by the optical demultiplexing element 9, and converted into electric signals in the light receiving elements 10 and 11, respectively. Then, the data signal and the reference signal converted into the electric signal are delayed by the electric signal delay circuit 12 and the electric signal delay circuit 13, respectively. Then, the reference signal of each channel is input to the phase comparison circuit 16, and the delay amount of the electric signal delay circuit 13 of each channel is appropriately set so that the reference signal can be synchronized. At this time, the data signal can be synchronized by setting the delay amount of the electric signal delay circuit 12 to be the same as the delay amount of the electric signal delay circuit 13.

Second Embodiment A second embodiment according to the present invention is shown in FIG. The optical transmitter 1 of this embodiment is the same as that of the first embodiment. That is, the optical output terminal 6 outputs a composite optical signal in which the reference optical signal is superimposed on the data optical signal. The optical receiving circuit 7 shown in the second embodiment is an optical signal delay circuit as a signal delay circuit.
I am using 17. Then, the composite optical signal is converted into an optical signal delay circuit.
After delaying at 17, the optical demultiplexing element 9 separates the data optical signal and the reference optical signal, and each of them is an electrical signal (data signal, reference signal) at the light receiving element (A) 10 and the light receiving element (B) 11. Convert to. Phase comparison circuit for reference signal of each channel
The delay amount of each optical signal delay circuit 17 is appropriately set so that the reference signal can be synchronized. As a result, the data signal of each channel can be synchronized.

[0010] A third embodiment according to the third embodiment the present invention shown in FIG. The optical transmitter 1 of this embodiment is the same as that of the first and second embodiments. That is, the optical output terminal 6 outputs a composite optical signal in which the data optical signal and the reference optical signal are combined. The optical receiver circuit 7 according to the third embodiment uses optical signal delay circuits 18 and 19 as signal delay circuits, as in the second embodiment. Here, after the composite optical signal is separated into the data optical signal and the reference optical signal by the optical demultiplexing element 9, in the optical signal delay circuit (A) 18 and the optical signal delay circuit (B) 19,
Each optical signal is delayed and converted into an electric signal (data signal / reference signal) in the light receiving element (A) 10 and the light receiving element (B) 11. Then, the reference signal of each channel is input to the phase comparison circuit 16 so that the reference signals can be synchronized,
The optical signal delay circuit 19 of each channel is set appropriately. At this time, by setting the delay amount of the optical signal delay circuit 18 equal to the delay amount of the optical signal delay circuit 19, the data signals can be synchronized.

In the second and third embodiments, the phase comparison circuit uses the reference signals of a plurality of channels converted into electric signals.
It is input to 16, and the delay amounts of the optical signal delay circuits 17, 18 and 19 are set based on the difference in the delay amount of each reference signal. However, before conversion to an electric signal, that is, the reference optical signal is input to the phase comparison circuit 16, and the delay amounts of the optical signal delay circuits 17, 18 and 19 are set based on the difference in the delay amount of the reference optical signal. It doesn't matter. At this time, the phase comparison circuit 16 receives the optical signal and generates a signal for controlling the delay amount.

[0012]

When the parallel optical transmission device of the present invention is used,
Since the signal delay amount is adjusted in a circuit manner, it is not necessary to equalize the length of the optical wiring, and the degree of freedom of the position where the optical transmission circuit is arranged is increased. Moreover, since the length of the optical wiring can be set arbitrarily, the minimum required optical wiring can be used, and the amount of optical wiring used is smaller than that of the conventional parallel optical transmission device. Can save Further, since there is no redundant optical wiring, neat connection and mounting between the optical input / output terminals can be performed.

In particular, when a parallel optical transmission device is constructed using a plurality of optical transmission circuits, the difference in optical wiring length becomes large, but the parallel optical transmission device of the present invention is most effective in such a case. Exert. Further, the signal delay due to the difference in wiring length due to the mounting of the electric circuit and the light emitting element, which occurs when the optical transmission system has a hybrid configuration, can be adjusted in a circuit manner.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a parallel optical transmission device according to a first exemplary embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a parallel optical transmission device according to a second exemplary embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a parallel optical transmission device according to a third exemplary embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of a conventional parallel optical transmission device.

[Explanation of symbols]

 1 Optical Transmitting Circuit 2 Electrical Signal Processing Circuit 3 Light Emitting Element A 4 Light Emitting Element B 5 Optical Multiplexing Element 6 Optical Output Terminal 7 Optical Receiving Circuit 8 Optical Input Terminal 9 Optical Demultiplexing Element 10 Light Receiving Element A 11 Light Receiving Element B 12 Electrical Signal Delay Circuit A 13 Electric signal delay circuit B 14 Electric signal processing circuit 15 Optical wiring 16 Phase comparison circuit 17 Optical signal delay circuit 18 Optical signal delay circuit A 19 Optical signal delay circuit B

Claims (4)

[Claims] 1. An optical transmission circuit having a plurality of optical output terminals for outputting an optical signal, an optical receiving circuit having an optical input terminal corresponding to the optical output terminal, an optical output terminal and the optical input terminal. In a parallel optical transmission device having a plurality of transmission channels configured by connecting optical wirings, the optical transmission circuit includes a light emitting element A that outputs a data optical signal.
A light emitting element B for outputting a reference light signal, and the light emitting element A
Output light of the light emitting element B and the output light wavelength of the light emitting element B are different from each other, and the output light wavelength of the light emitting element A and the output light wavelength of the light emitting element B are different from each other. Is output a composite optical signal obtained by combining the data optical signal and the reference optical signal, and the optical receiving circuit is an optical demultiplexing device for separating the composite optical signal into the data optical signal and the reference optical signal. A light receiving element A for converting the data optical signal into an electric signal, a light receiving element B for converting the reference light signal into an electric signal, and an electric signal delay for delaying the data signal converted into an electric signal by each light receiving element A A circuit A and an electric signal delay circuit B for delaying a reference signal converted into an electric signal by the light receiving element B, and the delay amounts of the electric signal delay circuit A and the electric signal delay circuit B are set equal to each other, The electrical signal delay circuit A of another channel and A parallel optical transmission device characterized in that a delay amount can be arbitrarily set independently of the electric signal delay circuit B. 2. An optical transmitter circuit having a plurality of optical output terminals for outputting an optical signal, an optical receiver circuit having an optical input terminal corresponding to the optical output terminals, and an optical output terminal and the optical input terminal. In a parallel optical transmission device having a plurality of transmission channels configured by connecting optical wirings, the optical transmission circuit includes a light emitting element A that outputs a data optical signal.
A light emitting element B for outputting a reference light signal, and the light emitting element A
Output light of the light emitting element B and the output light wavelength of the light emitting element B are different from each other, and the output light wavelength of the light emitting element A and the output light wavelength of the light emitting element B are different from each other. Outputs a composite optical signal obtained by combining the data optical signal and the reference optical signal, the optical receiving circuit delays the composite optical signal, and an optical signal delay circuit that outputs the composite optical signal to the data optical signal. The optical signal is composed of an optical demultiplexer for separating the reference optical signal, a light receiving element A for converting the data optical signal into an electric signal, and a light receiving element B for converting the reference optical signal into an electric signal. A parallel optical transmission device, wherein the delay amount of a delay circuit can be set independently for each channel and arbitrarily. 3. An optical transmitter circuit having a plurality of optical output terminals for outputting an optical signal, an optical receiver circuit having an optical input terminal corresponding to the optical output terminal, an optical output terminal and the optical input terminal. In a parallel optical transmission device having a plurality of transmission channels configured by connecting optical wirings, the optical transmission circuit includes a light emitting element A that outputs a data optical signal.
A light emitting element B for outputting a reference light signal, and the light emitting element A
Output light of the light emitting element B and the output light wavelength of the light emitting element B are different from each other, and the output light wavelength of the light emitting element A and the output light wavelength of the light emitting element B are different from each other. Is output a composite optical signal obtained by combining the data optical signal and the reference optical signal, and the optical receiving circuit is an optical demultiplexing device for separating the composite optical signal into the data optical signal and the reference optical signal. , An optical signal delay circuit A for delaying the data optical signal, an optical signal delay circuit B for delaying the reference optical signal, a light receiving element A for converting the data optical signal into an electrical signal, and an electrical reference signal The optical signal delay circuit A and the optical signal delay circuit B of other channels are configured by setting the delay amounts of the optical signal delay circuit A and the optical signal delay circuit B to be equal. It is possible to set the delay amount independently of Characteristic parallel optical transmission equipment. 4. The parallel optical transmission device according to claim 1, wherein the electrical signal delay circuit or the optical signal delay circuit is based on a reference signal of each channel or a difference in delay amount between the reference optical signals. A parallel optical transmission device having a function of setting the delay amount of the parallel optical transmission device.